Abstract: According to an aspect of the invention, a motor drive circuit includes a first energy storage device configured to supply electrical energy, a bi-directional DC-to-DC voltage converter coupled to the first energy storage device, a voltage inverter coupled to the bi-directional DC-to-DC voltage converter, and an input device configured to receive electrical energy from an external energy source. The motor drive circuit further includes a coupling system coupled to the input device, to the first energy storage device, and to the bi-directional DC-to-DC voltage converter. The coupling system has a first configuration configured to transfer electrical energy to the first energy storage device via the bi-directional DC-to-DC voltage converter, and has a second configuration configured to transfer electrical energy from the first energy storage device to the voltage inverter via the bi-directional DC-to-DC voltage converter.

Abstract: According to an aspect of the invention, a motor drive circuit includes a first energy storage device configured to supply electrical energy, a bi-directional DC-to-DC voltage converter coupled to the first energy storage device, a voltage inverter coupled to the bi-directional DC-to-DC voltage converter, and an input device configured to receive electrical energy from an external energy source. The motor drive circuit further includes a coupling system coupled to the input device, to the first energy storage device, and to the bi-directional DC-to-DC voltage converter. The coupling system has a first configuration configured to transfer electrical energy to the first energy storage device via the bi-directional DC-to-DC voltage converter, and has a second configuration configured to transfer electrical energy from the first energy storage device to the voltage inverter via the bi-directional DC-to-DC voltage converter.

Abstract: According to an aspect of the invention, a motor drive circuit includes a first energy storage device configured to supply electrical energy, a bi-directional DC-to-DC voltage converter coupled to the first energy storage device, a voltage inverter coupled to the bi-directional DC-to-DC voltage converter, and an input device configured to receive electrical energy from an external energy source. The motor drive circuit further includes a coupling system coupled to the input device, to the first energy storage device, and to the bi-directional DC-to-DC voltage converter. The coupling system has a first configuration configured to transfer electrical energy to the first energy storage device via the bi-directional DC-to-DC voltage converter, and has a second configuration configured to transfer electrical energy from the first energy storage device to the voltage inverter via the bi-directional DC-to-DC voltage converter.

Abstract: According to an aspect of the invention, a motor drive circuit includes a first energy storage device configured to supply electrical energy, a bi-directional DC-to-DC voltage converter coupled to the first energy storage device, a voltage inverter coupled to the bi-directional DC-to-DC voltage converter, and an input device configured to receive electrical energy from an external energy source. The motor drive circuit further includes a coupling system coupled to the input device, to the first energy storage device, and to the bi-directional DC-to-DC voltage converter. The coupling system has a first configuration configured to transfer electrical energy to the first energy storage device via the bi-directional DC-to-DC voltage converter, and has a second configuration configured to transfer electrical energy from the first energy storage device to the voltage inverter via the bi-directional DC-to-DC voltage converter.

Abstract: According to an aspect of the invention, a motor drive circuit includes a first energy storage device configured to supply electrical energy, a bi-directional DC-to-DC voltage converter coupled to the first energy storage device, a voltage inverter coupled to the bi-directional DC-to-DC voltage converter, and an input device configured to receive electrical energy from an external energy source. The motor drive circuit further includes a coupling system coupled to the input device, to the first energy storage device, and to the bi-directional DC-to-DC voltage converter. The coupling system has a first configuration configured to transfer electrical energy to the first energy storage device via the bi-directional DC-to-DC voltage converter, and has a second configuration configured to transfer electrical energy from the first energy storage device to the voltage inverter via the bi-directional DC-to-DC voltage converter.

Abstract: According to an aspect of the invention, a motor drive circuit includes a first energy storage device configured to supply electrical energy, a bi-directional DC-to-DC voltage converter coupled to the first energy storage device, a voltage inverter coupled to the bi-directional DC-to-DC voltage converter, and an input device configured to receive electrical energy from an external energy source. The motor drive circuit further includes a coupling system coupled to the input device, to the first energy storage device, and to the bi-directional DC-to-DC voltage converter. The coupling system has a first configuration configured to transfer electrical energy to the first energy storage device via the bi-directional DC-to-DC voltage converter, and has a second configuration configured to transfer electrical energy from the first energy storage device to the voltage inverter via the bi-directional DC-to-DC voltage converter.

Abstract: A fraction inverter circuit includes a first energy storage device configured to output a DC voltage, a first bi-directional DC-to-AC voltage inverter coupled to the first energy storage device, and a first electromechanical device. The first electromechanical device includes a first plurality of conductors coupled to the first bi-directional DC-to-AC voltage inverter, a second plurality of conductors coupled together, and a plurality of windings coupled between the first plurality of conductors and the second plurality of conductors. The traction converter circuit also includes a charge bus comprising a first conductor coupled to the second plurality of conductors of the first electromechanical device, the charge bus configured to transmit a charging current to or receive a charging current from the first electromechanical device to charge the first energy storage device via the first electromechanical device and the first bi-directional DC-to-AC voltage inverter.

Abstract: A traction inverter circuit includes a first energy storage device configured to output a DC voltage, a first bi-directional DC-to-AC voltage inverter coupled to the first energy storage device, and a first electromechanical device. The first electromechanical device includes a first plurality of conductors coupled to the first bi-directional DC-to-AC voltage inverter, a second plurality of conductors coupled together, and a plurality of windings coupled between the first plurality of conductors and the second plurality of conductors. The traction converter circuit also includes a charge bus comprising a first conductor coupled to the second plurality of conductors of the first electromechanical device, the charge bus configured to transmit a charging current to or receive a charging current from the first electromechanical device to charge the first energy storage device via the first electromechanical device and the first bi-directional DC-to-AC voltage inverter.

Abstract: A power converter generates direct voltage and includes a phase-shifted PWM bridge with first and second controllable switches connected as a half-bridge with a first tap, for generating AC at the first tap. An output transformer includes a primary winding coupled to the first tap. A full-wave rectifier is connected to a secondary winding of the output transformer. A filter is coupled to the full-wave rectifier for producing filtered output direct voltage. Resonances create surges which may undesirably result in energy loss. A second transformer includes a primary winding coupled to receive the resonant surges and a secondary winding at which transformed surges appear. A second rectifier is coupled to the secondary winding of the second transformer, for rectifying the surges. The energy of the surges is returned or coupled to the source or load. In one embodiment, the full-wave rectifier is a bridge rectifier.

Abstract: A traction inverter circuit includes a first energy storage device configured to output a DC voltage, a first bi-directional DC-to-AC voltage inverter coupled to the first energy storage device, and a first electromechanical device. The first electromechanical device includes a first plurality of conductors coupled to the first bi-directional DC-to-AC voltage inverter, a second plurality of conductors coupled together, and a plurality of windings coupled between the first plurality of conductors and the second plurality of conductors. The traction converter circuit also includes a charge bus comprising a first conductor coupled to the second plurality of conductors of the first electromechanical device, the charge bus configured to transmit a charging current to or receive a charging current from the first electromechanical device to charge the first energy storage device via the first electromechanical device and the first bi-directional DC-to-AC voltage inverter.

Abstract: According to an aspect of the invention, a motor drive circuit includes a first energy storage device configured to supply electrical energy, a bi-directional DC-to-DC voltage converter coupled to the first energy storage device, a voltage inverter coupled to the bi-directional DC-to-DC voltage converter, and an input device configured to receive electrical energy from an external energy source. The motor drive circuit further includes a coupling system coupled to the input device, to the first energy storage device, and to the bi-directional DC-to-DC voltage converter. The coupling system has a first configuration configured to transfer electrical energy to the first energy storage device via the bi-directional DC-to-DC voltage converter, and has a second configuration configured to transfer electrical energy from the first energy storage device to the voltage inverter via the bi-directional DC-to-DC voltage converter.

Abstract: A high frequency, full bridge, resonant DC to DC converter provides a main DC output voltage that is regulated by adjusting the phase shift of the input power to a main input transformer and at least one additional DC output voltage that is regulated on the secondary side of the power input transformer. A main DC output voltage is regulated by a full bridge resonant switching converter with lossless switching of input power devices. At least one additional secondary winding on the transformer supplies a second DC output voltage that is regulated independently of the main DC output voltage. Two switching devices are used for each auxiliary DC output to regulate each auxiliary output voltage by adjusting the length of the on time of the pulses from the transformer's auxiliary secondary windings. Soft switching techniques are used to ensure that the switching devices turn on when the voltage across them is effectively zero.

Abstract: The present invention provides a switching power supply which operates at a high efficiency over a wide operating load range. When the output power is below a first power level, the first power converter stage operates in a hard-switching mode and the second power converter stage is off. When the output power is greater than the first power level and less than a second power level, the first power converter stage operates in a soft-switching mode and the second power converter stage is off. When an output power is greater than the second power level, the first power converter stage operates in a soft-switching mode and the second power converter stage operates in a soft-switching mode.

Abstract: Power is transferred from a stationary power supply to a rotational gantry in a computer tomography (CT) system through a rotary transformer arranged in a ring configuration with an inner diameter that is sufficiently large to receive a patient. The rotary transformer has a toroidal rotor core and a toroidal stator core arranged either concentrically with an air gap extending radially therebetween or side-by-side with an air gap extending axially therebetween. A resonant inverter provides ac power to the rotary transformer which, in turn, drives a high-voltage tank circuit coupled to a x-ray tube, the tank circuit and x-ray tube being mounted on a rotational gantry. Advantageously, this is a contactless power transfer system which eliminates conventional brush and slip ring arrangements and moreover avoids the need for mounting the inverter to rotate with the CT gantry.

Abstract: A dc-to-dc power converter, comprising a transformer, a single primary-side power switching device and a parallel combination of a diode and a capacitance, is controlled to operate in a "natural" zero-voltage switching mode such that the power switching device is switched with zero-voltage thereacross. Due to the simplicity of the circuit, i.e., very few components, and its high-frequency capability, it can be implemented using high-density packaging techniques. Such a converter is useful in ultra-high-density point-of-load dc-to-dc converters for distributed power systems.

Abstract: A front end converter for interfacing prime power to a lower voltage distribution bus, e.g., Vdc, in a distributed power system has a natural droop characteristic which emulates a series resistor, but without associated losses. With this droop characteristic, converters are paralleled and share load current without any interconnecting control signals, thus avoiding any single point of failure and the need for several high-voltage isolation devices. The drooping effect also has a damping effect, resulting in a more stable power system.

Abstract: A transformer having a very low, predetermined leakage inductance includes an elongate dielectric laminate having two surfaces. A primary winding having a pattern conformal to the configuration of the laminate is disposed on one surface and extends substantially the length of the laminate. The laminate has at least one secondary winding disposed on its other surface. The laminate is rolled with a dielectric layer about a cylinder, and the primary and secondary windings are patterned such that the primary and secondary windings comprise interleaved winding layers with the dielectric layer disposed between each of the winding layers. The rolled laminate, dielectric layer, and windings are contained within a cylindrical magnetic pot core. The result is a transformer having tightly interleaved primary and secondary windings and, therefore, a very low leakage inductance.

Abstract: A converter for an ac power distribution system provides a square-wave voltage of low output impedance to an ac power distribution bus for driving a plurality of loads, each load including a rectifier and an input filter capacitor. Slew-rate limiting capacitors are employed to limit the rate of change of voltage on the ac distribution bus, thereby substantially reducing or eliminating conducted and radiated interference from the power distribution system due to high-frequency components of current which would otherwise flow in parasitic capacitances. In addition, zero-voltage switching is employed to achieve highly efficient converter operation. As other advantages, this converter scheme allows for simplification of converters at the load end of the power distribution system (e.g., to simple rectifiers with post regulators), while producing lower ac line currents, lower current harmonics and higher power factors than those of a sine-wave generation system.

Abstract: Low-power auxiliary circuitry is added to a resonant converter for providing high efficiency operation, low EMI, and tight output voltage control over a wide load range. There is an auxiliary circuit corresponding to each half-bridge connection of main switching devices, each auxiliary circuit including a half-bridge connection of auxiliary switching devices with the junction therebetween coupled to the junction between the main switching devices of the corresponding half-bridge. Under heavy load conditions, sufficient energy is stored in the main resonant inductor to commutate the junctions joining the main switching devices in the resonant converter, resulting in zero-voltage switching for the main switching devices.

Abstract: A gate driver circuit, including either a full-bridge or a half-bridge configuration of gate drive switching devices, is capable of applying gate drive signals of variable pulse widths in a substantially loss,less manner to power switching devices of a high-frequency resonant switching converter, while providing transformer isolation between the gate drive electronics and the power switching devices.